Autopilot for jet belt



Dec. 17, 1968 J. K. HULBERT AUTOPILOT FOR JET BELT Filed June 22. 1966 M w J 8 ilxmm y 1 m ii; m cm Nb ms 00 I Ii, lilillillnzi,

A TTORNEYS United States Patent 3,416,753 AUTOPILOT FOR JET BELT John K. Hulbert, Grand Island, N.Y., assignor to Bell Aerospace Corporation, Wheatfield, N.Y. Filed June 22, 1966, Ser. No. 559,563 3 Claims. (Cl. 2444) ABSTRACT OF THE DISCLOSURE An individual propulsion device for rendering a person airborne including jet propulsion means, a gas generator for feeding the jet propulsion means, a throttle mechanism for controlling the volumetric flow of gases emanating from the jet propulsion means and a mechanism for sensing accelerations and automatically controlling the device to compensate for the accelerations. The throttle mechanism is attached to a balance piston assembly which is in turn operatively connected to a bob weight acceleration sensing device which operates to open valve means to the balance piston assembly upon any vertical acceleration.

This invention relates to control mechanisms for devices utilized in rendering an individual airborne and pertains, more particularly, to mechanism for sensing accelerations along a vertical axis for controlling ascent, descent and hovering so that the operator need not participate in the control of such movements whereby he may be released to perform other tasks.

In devices for rendering individuals airborne such as are disclosed in Patent No. 3,021,095 issued Feb. 13, 1962 and copending application Ser. No. 383,271 filed July 17, 1964, some type of throttle device is used for controlling the assemblage for movement along the vertical axis; that is, for ascent, descent and hovering. The nature of such controls requires constant attendance by the operator and, for this reason, the operators throttle-controlling hand cannot be released for other duties as may be required such as for example, in assembling, adjusting or repairing other airborne mechanisms. Consequently, it is of primary concern in connection with this invention to provide an automatic throttle control mechanism which is sensitive to accelerations along a vertical axis and which utilizes such accelerating force or forces to appropriately control the throttle mechanism. At the same time, it is of principal concern herein to achieve such objective by mechanism which is simple, eflicient and economical.

More particularly, it is an object of this invention to provide a mass accelerometer type of mechanism operating in conjunction with a mechanical transducer connected to the throttle actuating mechanism of devices of the character described. In this manner, hands-off control under zero acceleration conditions, that is, under constant velocity or descent or under hovering conditions, may be effected.

Still more specifically, it is an object of this invention to provide a control device as aforesaid wherein the actuating medium is readily available incidental to operation of the mechanism which renders the individual airborne and, in particular, it is an object of this invention to utilize pneumatic pressure differential to effect throttle setting variations so as to maintain zero acceleration conditions automatically while enabling the operator to use his throttle-controlling hand for other duties such as assembling, repair or the like.

Other objects and advantages of the invention will appear from the following specification and the accompanying drawings wherein:

FIG. 1 is an elevational view showing an individual ice having attached mechanism for rendering him airborne and also showing the relative disposition of the component parts according to the present invention; and

FIG. 2 is an enlarged sectional view taken through the mechanism according to the present invention and further illustrating its operative association with the device for rendering an individual airborne.

With reference now more particularly to FIG. 1, the reference character 10 indicates a corset assembly which is relatively rigid and which is adapted to be snugly engaged about a users waist and to extend upwardly along his back so that the individuals body, and more particularly his torso, is rendered relatively rigid and immobilized. The corset 10 rigidly afiixes a propulsion unit indicated generally by the reference character 12 which, in the specific instance shown, consists of a turbine assembly 14 surrounded by a fuel tank 16 and arranged vertically to induct air upwardly through the inlet horn 1'8 and to discharge air and products of combustion into the dome 20 for manifolding to a pair of flexible conduit assemblies, one of which is shown and indicated by the reference character 22. A cross arm assembly (not shown) is pivotally attached to the upper rear extremity of the corset 10' just behind the users neck for universal pivotal movement relative to the corset 10 and each of these flexible conduits discharges to a downwardly directed jet nozzle 24 fixed to the cross arm assembly. Also secured to the cross arm which carries the jet nozzles 24 is a forwardly extending control bar 26 which may terminate at its forward extremity in a pair of depending control handles such as indicated by the reference character 28. The cross arm assembly also carries a pair of shoul der engaging means such as the strap loops 30 which engage around the users shoulder and beneath his arm pits. The mechanism briefly described hereinabove operates according to the principles set forth in Patent No. 3,021,095 issued Feb. 13, 1962, and more particularly in accord with the disclosure according to copending application Ser. No. 383,271 filed July 17, 1964.

Briefly, the operation of the device is simply to expel gases through the nozzles 24 to impart an uplifting force to the user. In the course of operation, the individual or user is suspended primarily by the shoulder engaging means such as the strap loops 30 and partially by groin straps 'such as are indicated by the reference character 32 and which are secured to the lower extremity of the corset 10 to engage with the users groin. The cross arm which carries the jet nozzles 24 is pivoted relative to the corset 10 for kinesthetic control as achieved by the individual to effect movements of the man-machine combination in pitch and roll, all as has been set forth in the aforesaid patent and copending application. Obviously, it may be desirable to permit an individual thus rendered airborne to perform duties or tasks upon some other airborne object or body and, for this reason, it would be desirable to release one or more of the operators hands for such duties. To accomplish this, the mechanism indicated by the reference character 34 in FIG. 1 is utilized in accord with the present invention. The assembly 34 consists essentially, as can be seen in FIG. 2, of mechanical transducer or balance piston assembly 36 and an accelerometer device 38 associated therewith. To appreciate the operation of the instant device, it will be understood that one of the control handles 28 of the above described mechanism is utilized to control the throttle of the power plant 12. In the specific instance shown in FIG. 1, the handle 28 is provided with a rotatable hand grip 40 which operates through a suitable cam or other mechanism to control a bell crank 42 having a pivot point as at 44 and which is connected to one end of a Bowden cable 46. The other end of the Bowden cable 46 is connected to an intermediate lever 48 suitably pivoted as at 50 (see particularly FIG.

2) and which intermediate lever 48 is pivotally connected as at 52 to an actuator rod 54 of the transducers assembly 36. The intermediate lever 48 also connects to a vertical cable such as the Bowden wire 56 which leads to the throttle mechanism of the power plant 12. Thus, actuation of the handle 40 not only moves the actuator rod 54 but it also operates the power plant throttle control mechanism through the intermediary of the Bowden cable 56. Conversely, the actuator rod 54 is capable, as will hereinafter he described, of imparting throttle control movements to the power plant throttle control by means of the actuator cable 56.

The manner in which the automatic control for the power plant throttle mechanism is achieved is by fluid valving as achieved by the accelerometer device 38. The accelerometer device consists simply of an elongate cylinder having an axis 58 oriented parallel to the vertical center-line 60. Slidably received within the vertical cylinder 62 is a mass or weight 64 which is normally urged to a centered position therewithin under the action of a pair of compression springs 66 and 68. The opposite ends of the cylinder 62 carry adjusting screws 70 and 72 which bear against plates 74 and 76, respectively, upon which the two springs 66 and 68 are seated. Thus, the two adjusting screws 70 and 72 may be utilized to zero, the accelerometer device. The cylinder 62 is provided with a pair of ports 78 and 80, both of which are normally covered or closed by the bob weight 64 when such weight is in the centered position and under the action of zero acceleration along the vertical axis. The cylinder 62 is also provided with end ports 82 and 84 substantially as shown.

The transducer 36 consists essentially of a movable wall member 86 to which the actuator rod 54 is connected and which movable wall member forms, with the body 88, a pair of pressure chambers 90 and 92. As can be seen, the 78 is connected to the pressure chamber 92 whereas the port 80 is connected to the pressure chamber 90. It will also be seen that the pressure chambers 90 and 92 are provided with ambient pressure vents 94 and 96 to prevent fluid lock. The end ports 82 and 84 are connected through a suitable conduit 98 to a source of fluid pres sure and, more especially, the conduit 98 extends to a pressure zone within the turbine assembly 14. Thus, the two chambers 100 and 102 on either side of the mass weight 64 are subjected to the same positive pneumatic pressure. Consequently, if the weight 64 shifts under the influence of an acceleration force along the axis 58, one or the other of the ports 78 or 80 will be uncovered or partially uncovered so that the corresponding pressure chamber 90 and 92 will be subjected to the positive pneumatic pressure existing in the two chambers 100 and 102, whereas the other or remaining pressure chamber 90 'or 92 Will be subjected to ambient pressure. The pressure differential so effected will operate to move the wall memher 86 and thereby actuate the throttle of the turbine assembly 14 in such sense as to counter the acceleration force which caused movement of the weight 64.

As a result of the above, the operator may initiate a condition of zero acceleration along the vertical axis 58 such as hovering or constant velocity ascent or descent, and thereafter remove his hand from the manual throttle control and be assured of being automatically maintained in such zero acceleration condition. In this way, the operators throttle control hand is released for other duties, as may be necessary.

I claim:

1. In an individual propulsion device for rendering a person airborne including jet propulsion means and a gas generator for feeding said jet propulsion means, control mechanism for altering the line of thrust of the jet propulsion means, and a throttle mechanism for controlling the volumetric flow of gases emanating from said jet propulsion means, the improvement consisting of:

a balance piston assembly connected to said throttle mechanism,

valve means connected to opposite sides of said balance piston asembly and having connection to said gas generating means,

and a bob weight, consisting of a single cylindrical member, oriented for motion along a vertical plane and normally centered under zero gravity conditions to block the valve means to both sides of said balance piston assembly but being movable under positive or negative gravity conditions to bleed gas from said gas generating means to one side or the other of said balance piston assembly to operate on said throttle mechanism in a sense to cancel the gravity force acting.

2. In the assembly as defined in claim 1 wherein said valve means comprises an elongate tube having a pair of centrally disposed ports connected to the opposite side of said balance piston assembly, said bob weight being spring urged to normally cover both of said ports.

3. The assembly as defined in claim 2 including means for adjusting the zero gravity position of said bob weight within said cylinder.

References Cited UNITED STATES PATENTS 3/1946 Goddard 24476 v,2/ 1962 Moore 2444 7/ 1962 Gaynor et al. 24478 US. Cl. X.R. 24478 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,4l6,753 December 17 1968 John K. Hulbert It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, lines 27 and 41, "zero gravity", each occurrence, should read zero acceleration Signed and sealed this 24th day of March 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Edward M. Fletcher, Jr.

Attesting Officer 

